Multi-stage energy storage for high-efficiency thermoelectric harvesting in gas turbine

Gas turbines generate substantial waste heat during operation, yet traditional energy harvesting systems fail to efficiently utilize this resource due to inadequate energy management and storage under fluctuating temperature gradients. This study presents a multi-stage energy storage system integrated with a thermoelectric generator (TEG) module to enhance waste heat recovery and ensure stable power delivery for gas turbine sensor networks. The TEG is built into the gas turbine shaft wall to capture low-grade heat energy consistently, which is then processed by a hierarchical storage system. The multi-stage energy storage, combining a rapid-response primary storage unit with a high-capacitance secondary storage unit, dynamically allocates surplus energy during high-temperature gradients and compensates for power deficits during low-gradient conditions. Experimental results demonstrate that the multi-stage energy storage system achieves rapid and stable power delivery to the load within 2 seconds during high-temperature gradients while simultaneously collecting surplus energy. Moreover, compared to single-stage storage systems, it can extend the system's operational time by approximately 40 times during energy scarcity by utilizing the collected surplus energy. This synergistic design improves waste heat utilization efficiency, enabling reliable self-powered monitoring of gas turbine health.